Diffusion of point source pollutants in the tee structure

Abstract

The tee structure is an integral part of the water distribution system, and pollutants diffuse in complex ways within the structure. In this paper, the diffusion pattern of contaminants in the tee structure was examined using a combination of numerical simulations and experiments. The coefficient of variation was chosen as an evaluation indicator, and the uniform diffusion length (LU) was defined to quantify the location of uniform diffusion of pollutants in the structure. Several factors were used to investigate pollutant diffusion in the pipe, including pipe diameter, break location, inlet Reynolds number, outlet flow ratio, brine flow rate, and brine density. Results show that the inlet Reynolds number, outlet flow ratio, and pipe diameter all significantly affect pollutant diffusion. The LU increased as the inlet Reynolds number, outlet flow coefficient, and pipe diameter increased. In addition, equations for calculating LU were fitted using dimensional analysis and can be used to predict LU under other conditions as well. HIGHLIGHTS The primary and secondary factors influencing the diffusion of pollutants within the tee structure were determined by an orthogonal test.; The influence of primary factors on the diffusion of pollutants was investigated using a full factorial experiment.; Quantitative equations were fitted to predict the uniform diffusion length of point source pollutants in the tee structure.;

Keywords

• dimensional analysis
• pollutant diffusion
• species transport model
• tee structure
• uniform diffusion length